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Thoracic Vertebræ
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical and lumbar vertebrae; they increase in size going towards the lumbar vertebrae, with the lower ones being much larger than the upper. They are distinguished by the presence of facets on the sides of the bodies for articulation with the heads of the ribs, as well as facets on the transverse processes of all, except the eleventh and twelfth, for articulation with the tubercles of the ribs. By convention, the human thoracic vertebrae are numbered T1–T12, with the first one (T1) located closest to the skull and the others going down the spine toward the lumbar region. General characteristics These are the general characteristics of the second through eighth thoracic vertebrae. The first and ninth through twelfth vertebrae contain certai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrates
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species '' Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intervertebral Foramen
The intervertebral foramen (also called neural foramen, and often abbreviated as IV foramen or IVF) is a foramen between two spinal vertebrae. Cervical, thoracic, and lumbar vertebrae all have intervertebral foramina. The foramina, or openings, are present between every pair of vertebrae in these areas. A number of structures pass through the foramen. These are the root of each spinal nerve, the spinal artery of the segmental artery, communicating veins between the internal and external plexuses, recurrent meningeal (sinu-vertebral) nerves, and transforaminal ligaments. When the spinal vertebrae are articulated with each other, the bodies form a strong pillar that supports the head and trunk, and the vertebral foramen constitutes a canal for the protection of the medulla spinalis (spinal cord). The size of the foramina is variable due to placement, pathology, spinal loading, and posture. Foramina can be occluded by arthritic degenerative changes and space-occupying les ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orientation
Orientation may refer to: Positioning in physical space * Map orientation, the relationship between directions on a map and compass directions * Orientation (housing), the position of a building with respect to the sun, a concept in building design * Orientation of churches, the architectural feature of facing ("orienting"), churches towards the east (Latin: oriens) * Coin orientation, a description of the orientation of opposite faces of a coin with respect to one another * Page orientation, the way in which a rectangular page is oriented for normal viewing * In Animal navigation, turning the body to a desired heading, e.g. in the correct direction of migration * Orientation (sign language), the orientation of the hands when signing Arts and media * ''Orientation'' (EP), a 2001 album by Sonata Arctica * ''Orientation'' (film), a 1996 short film produced by the Church of Scientology * "Orientation" (''Lost''), a 2005 episode of American television series ''Lost'' * "Ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
